Thermostatic air circulation control



Aug. 24, 1948.

H. A. WHEELER THERMOSTATIC AIR CIRCULATION CONTROL Filed Feb. 11, 1946 2Sheets-Sheet 2 M0 L0 AMHEELER M ATTO RNEY 5 \NVEN TOR atented Aug. 24,1948 UNITED STATE s PATENT OFFICE AIR CIRCULATION THERMO STATIC Mich.

NTROL Harold A. Wheeler, Grand or to Raymond J. Scheffler,

Rapids, Micln, assign- Grand Rapids,

7 Claims.

The present invention relates to a control of the motor of an air fan orblower, for varying the speed of rotation of the motor and, therefore,of the fan, governed by the temperature of the air which is being forcedby the fan out of the fan or blower housing. A constant speed electricmotor is the prime mover preferably, in connection with this invention,and is used to drive a hydraulic pump, the liquid pumped thereby beingcarried to a hydraulic motor, the speed of rotation of which is inproportion to the quantity or amount of liquid which is pumped to it.With my invention, the flow of liquid pumped from the hydraulic pump tothe fan connected hydraulic motor is automatically varied and iscontrolled by thermostatic means which is utilized to govern the area ofpassage of the liquid pumped by the pump, so that the liquid going fromthe pump to the motor is greater or less in accordance with the greateror less area of the passage therefor. In combination and associationtherewith, means are provided for a return to the liquid supply of suchliquid pumped by the pump, which can not pass. to the motor.

The invention is utilized in conjunction with the forcing or blowing, bya fan blower, of air of a raised temperature to a room or rooms of ahouse or building. the driving speed of the fan being decreased thehigher the temperature of the air circulated or forced to a room orrooms to be heated, and increased when the temperature of the air islowered.

It is a primary object and purpose of the present invention to provide avery effective, practical and serviceable unit for automaticallyachieving the variable operation of a blower fan from a constant speeddriving motor and dispense with ex ensive rheostat controls for anelectric motor and also eliminate any necessity of using special fanconstruct ons wh ch may be adiusted. usually manually. to servedifferent conditions of service.

An understanding of the invention may be had from the followingdescription taken in connection with the accompanying drawings. inwhich- Fig. 1 is a side elevation, partly in section, of thethermostatic control installation of my invention.

Fig. 2 is a s milar view at right angles to Fig. 1, showing an endelevation of the blower housing.

Fig. 3 is a vertical section through the hydraulic pump and themechanism used to thermostatically control its working liquid passagetherefrom.

Fig. 4 is a fragmentary vertical section through the pipe at rightangles to the section shown in Fig. 3.

Fig. 5 is a transverse vertical section through the hydraulic motoroperated from the pump, and

Fig. 6 is a longitudinal vertical section therethrough.

Like reference characters reier to like parts in the different figuresof the drawing.

Within an closed compartment I, the air which is to be placed underforced circulation by the blow-er fan is entered through an inlet pipeor conduit 2. The blower fan housing 3 has an outlet 4 extending fromthe compartment and within the housing any conventional form ofrotatable fan blower 5 is mounted being shown mounted for rotation abouta horizontal axis, at one end upon a hearing at a side of the housing 3and at the other side having a shaft 6 which is directly connected withthe rotor of a hydraulic motor.

The hydraulic motor (Fig. 6) comprises a casing 1 open at both ends andclosed at its ends by end plates 8 and ii, the latter having arelatively extended bearing for a sleeve in extending from the rotor llof the motor which is eccentrically mounted within the cylindricalchamber within the housing I. The shaft 6 extends into the sleeve in(Fig. 6) and may be keyed or corn nected as shown by a set screw. Therotor H is of the conventional type used in hydraulic motors carryingdiametrically mounted movable vanes l2. The detail of the hydraulicmotor need not be entered into as such type of motor is well known.

The motor is preferably mounted upon an angle bar support l3 secured ata side of the blower housing 3, utilizing two clamping brackets or bandsl4 and I5, one passing underneath the casing I and the other over it andboth secured to the support 13 by bolts as shown in Fig. 5.

The motor is supplied with inlet and outlet pipes or conduits l6 and I!connected with the interior chamber. The liquid under pressure fordriving the rotor I I is supplied through the inlet pipe l6 and theexhaust or return of the liquid is through the pipe l1. Both of saidpipes are connected, at their opposite ends with the housing or casing[8 of a hydraulic pump which is preferably supported by supportingstandards l9 which may rest upon the floor of the compartment I.

The housing or casing l8 of the pump has a cylindrical recess bounded bycylindrical walls 20 adjoining and associated with which is a liquidsupply chamber 2| (Fig. 3) for supplying liquid to the pump. The returnof the exhaust liquid from the hydraulic motor previously described isto the chamber 2| as shown in Fig. 3. The rotor 22 of the hydraulic pumpis of cylindrical form eccentrically located in the cylinder 20 andhaving the diametrically positioned vanes '23 of usual construction.

The outlet of liquid forced or pumped outwardly is through an outletpassage 24 in communication with the pipe l6, which is connected to theinlet of the hydraulic motor.

A cylindrical sleeve 26 is mounted across and extends at its inner endbeyond the inner side of the sleeve 25. extending across the verticaloutlet passage 24 and, as shown in Fig. 4, the exterior diameter of thesleeve or cylinder 26 is less than the interior diameter of the passage24-. In said cylinder 26 two pairs of openings 2'! and 28 are cut in itsupper and lower sides. The openings 27 are made through the cylinder 25within the passage at at, while the openings 28 are at the inner endportion of the cylinder 25 and beyond the adjacent side of the sleeve25, or in the chamber 2!.

A piston rod 25 is equipped with two spaced pistons 35 and 3! as shownin Fig. 3, and extends through the outer end of the cylinder 26. Thepistons 39 and 3! are so located within the cylinder 26 with respect tothe openings 21 and 26 therein that, when located as shown inFig, 3,with the openings 28 covered by the piston 3d, the openings at 21 areopen to their full extent, in which case all of the liquid pumped by therotary pump will to and through the pipe H5, passing through thevertically alined passage 27 and at opposite sides of the cylinder 2'6.But with the piston rod 29 and the pistons 30 and 3! thereon moved tothe right the openings at 23 will be uncovered more or less, dependingupon the extent of movement, and the passage through the verticallyalined openings 2? will be reduced to a greater or less extent, andthere will be provided passage of liquid from the pump through the loweropening 29 and thence to the lower opening 28 so that a part of theliquid taken from the chamber 2! will be returned to such chamberwithout passing through the liquid circuit of pipe It, the fan drivingmotor and return pipe ill. When such flow of liquid is thus lessened,the hydraulic motor connected with the fan blower will receive only apart of the pump output and its speed of rotation will becorrespondingly reduced.

An open frame housing 32 is connected at one side of the casing orhousing l8, its horizontal axis being coincident with the axis of thepiston rod 29, within this housing an expansible and contractablethermostatic element is located, including a flexible metallic bellows33 sealed and closed at its outer end by a closure plate 34 which may beadjusted with respect to the outer end of the housing 32 by theadjusting screw 35 as shown. The other end of the expansible andcontractable bellows is closed and sealed by a plate 36 the centralportion of which has a relatively deep cylindrical recess 31 thereinagainst the bottom of which a head at the outer end of the piston rod 29is seated. A coiled compression spring 38 at its outer end bears againstthe head at the outer end of the rod 29, and at its opposite end againstthe housing or casing I 8.

The position of the pistons 38 and 3! is therefore governed by thethermostatically expanding and contracting bellows element, sometimesknown as a Sylphon, which elongates with increases in temperature andcontracts. with decreases in temperature due to the expansion andcontraction of the gaseous material which is sealed within suchthermostatic Sylphon element.

Such thermostatic bellows is old and well know: and has been used. inmany relations. Thus when the temperature of the air supplied throughthe pipe 2 to the chamber l is high, causing the thermostatic bellows toexpand and elongate, the openings at 27! will be closed in effectivepassage areas by the piston 3! in accordance with the degree or extentof expansion of the thermostatic bellows, with a correspondingcurtailment or diminution of the flow of liquid pumped by the hydraulicpump to the fan driving hydraulic motor; and when the temperature of theair supplied to the pipe 2 is lowered the effective passage openings 21will be increased and the fan driving motor will be correspondinglystepped up in its speed of rotation, so that with varying quantities ofair circulated by the fan blower the quantity of heat measured inthermal units supplied may be rendered substantially constant.

The hydraulic pump is driven by an electric motor 39, the shaft 46 ofwhich is connected with extension fill tothe rotor 22 of the pump. Thepump chamber is closed by end plates one of which has a relatively longbearing extension 22 in which said rotor extension 4| is rotatablymounted (Fig. 4).

With the construction described varying quantitles of air supplied toheat desired spaces in the way of rooms, houses or buildings, with thesupplying substantially of an even and constant quantity measured inunits 01- heat despite temperatures of the air which carries the heatmay be obtained; using a constant speed driving motor for the unit todrive a hydraulic pump at a constant speed, but with a control of theliquid pumped by the pump to carry varying quantities thereof to thehydraulic motor connected with and driving the fan blower. Such controlis thermostatically operated in conjunction with the temperature of theair which is to be circulated by the fan blower, said fan blower beingdriven at less speed with air of higher temperatures and at greaterspeeds with air at lower relative temperatures.

, The construction is compact, easily manufactured and assembled, isadjustable for substantially all working conditions met with, isrelatively economical to produce, and in general has proven verysatisfactory.

The invention is defined in the appended claims and is to be consideredcomprehensive of all forms of structure coming within their scope.

I claim:

1. In a construction as described, a rotatably mounted fan, a hydraulicmotor for driving said fan, a hydraulic pump for driving said motor, acontinuous speed motor for driving the pump at a continuous speed, andvalve means interposed between said pump and. the fan driving motor forcontrolling the passage of hydraulic fluid from the pump to said motor,combined with temperature actuated means for automatically controllingsaid valve means in accordance with the temperatures to which saidtemperature sensitive means is exposed.

2. 81ellfl"= S of claim 1 in which said valve means acts to bypassliquid from the outlet to the inlet side of said pump.

3. In a structure as described, an enclosed com-- partment having aninlet for the conducting of air at varying temperatures thereinto, ablower housing in the compartment having an outlet extending through awall of and away from said compartment, a rotatable fan mounted withinsaid housing, a hydraulic motor for driving the connected with saidvalve means to move the valve toward or to open position on contractionof said temperature sensitive means, and in the opposite directon topartially reduce the quantity of liquid pumped by said pump to thehydraulic motor, the degree of reducing said liquid flow increasing uponincreases of temperature of air supplied to said compartment and towhich air said temperature sensitive means is exposed.

4. A construction as defined in claim 3, said valve means including acylindrical sleeve extending across the passage in said conduit meansbetween said pump and hydraulic motor, the sleeve having an exteriordiameter less than the interior diameter of the passage, and said sleevehaving opposed openings through its sides within the said passage, apiston rod extending between said temperature sensitive expanding andcontracting means into said cylindrical sleeve, and a piston within thesleeve on said rod adapted to be moved between positions in which saidopenings through the sleeve are wholly uncovered or partially covered bysaid piston.

5. In a construction as described, a blower housing having air inlet andoutlet, a fan blower mounted for rotation within the housing, ahydraulic motor connected to said fan for rotatably driving it, ahydraulic pump for driving said pump said hydraulic pump including ahousing with an outlet thereto having a passage for the flow of liquidpumped for said pump, a cylindrical sleeve positioned across saidpassage and carried between pump housing, said sleeve having opposedopenings through its sides spaced from each other in the direction ofsaid passage, a piston rod extending into one end of the sleeve. apiston of said rod within the sleeve, an expanding and contractingthermostatic bellows adapted to be held in a fixed position at one endrelative to said sleeve,

the other end being movable towards or away from said sleeve uponincreases or decreases or the temperatures to which the bellows isexposed, the outer end of said piston rod bearing against said movableend of the bellows, a compression spring between the bellows and thepump housing, and a conducting pipe between said hydraulic motor and thepump housing in conjunction with the outlet passage from said pump.

6. A construction as defined in claim 5, and means for adjustablymounting the outer end of said bellows for adjustment towards or awayfrom said pump housing and for holding it fixed in any position to whichadjusted.

' 7. A construction as defined in claim 5, said pump housing includingwalls surrounding an oil supply chamber, a return pipe leading from thehydraulic motor to said chamber, said sleeve extending at its inner endinto said chamber, and said sleeve having additional openings atopposite sides within the chamber, and a second piston on said pistonrod located distances apart greater than the spaces between the openingsin the sides of said sleeve from each other.

HAROLD A. WHEELER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 40 Number Name Date 2,178,864 Rosenberger Nov. 7,1939 2,297,237 Nallinger Sept. 29, 1942 2,377,199 Adams et al May 29,1945

